The aim of this project is to characterize schistosome molecules relevant to immunity and pathogenesis, to analyze the molecular basis of physiologically important parasite processes which could serve as targets for intervention, and to develop and test recombinant vaccines. Progress was achieved in the following areas: A. Construction of elastase and glutathione S-transferase BCG vectors Recombinant BCG vectors expressing either elastase or glutathione S- transferase were constructed as candidate vaccines for preventing schistosome infection. B. Development and testing of protective T cell lines and clones A T cell line and clone were developed which transfer protection against challenge infection. The cytokine production patterns of the cells were characterized, and a study of their antigenic specificities initiated.